This invention relates to food products and a process for their preparation to produce a multi-curdled milk product with an acceptable and palatable flavor. More specifically, this invention relates to a unique multi-curdled milk product that employs a process that reduces the disaccharide sugar or lactose more completely than heretofore thought possible thereby increasing the amount of glucose and galactose. Prior milk products that have been prepared by multiple fermentation have used either alcohol or heat during the preparation which have the effect of hindering the enzymatic transformation of lactose to glucose and galactose. The use of alcohol in a milk product through some form of fermentation with yeast inhibits some of the enzymes normally present in milk and produces food of lessened nutritional content. Moreover, some people are allergic to the lactose in milk itself and are, therefore, denied the benefits of a milk product. For millions of people, intolerance develops during the life cycle such that they are unable to easily digest lactose, a condition that is believed to arise from the deficiency of B-galactosidase in the intestinal microville.
Previously, bacteria used as starters for culturing various types of milk base products have included spherical types such as Streptococcus lactis, Streptococcus cremoris, Leuconostoc citrovorum, Streptococcus diacelelactis, and Streptococcus durans which are used primarily for buttermilk and sour cream while rod-shaped types such as Lactobacillus bulgaricus, Lactobacillus helveticus, Lactobacillus lactis, Lactobacillus acidophilus, Actinomyces bifidus, and Doderlein's bacillus are used primarily for yogurt-like products. However, such milk base products generally have a lactose content after one culturing still higher than it need be.
In previously developed processes, the lactose was broken down by various fermentation processes converting the lactose into lactic acid as when milk with or without non-fat milk solids, partly skim milk or skim milk is changed into yogurt or buttermilk; however, over 80 percent of the disaccharide sugar may remain unspent after the buttermilk and sour cream fermentation is completed. Further efforts to remove the lactose have resulted in the past in lowering the nutritional value of the milk product or producing products that are unpalatable.
It has also been incorrectly assumed that cultures must be balanced when used together. One culture will reach a peak at which curd starts to separate from the whey. At this point, the addition of different varieties of souring cultures will produce new curdling as though no souring had occurred when the product is brought to a temperature suitable for optimal growth. Here, temperature is the controlling factor. L. bifidus and L. acidophilus, however, will culture separately at the same temperature if introduced at different times, especially when the first culturing is cooled and blended.
An inexpensive process to produce milk products digestable to the multitude of persons who cannot drink it would have far-reaching effects, particularly if substantial quantities of lactose can be transformed without altering the nutritional value of the milk product, except to improve it.
The therapeutic value of inoculating milk with various strains of microorganisms has been reported by numerous authorities and this is particularly true for maintaining a good intestinal metabolism and health. Three species of such microorganism cultures include L. bifidus, L. acidophilus, and L. bulgaricus. L. bulgaricus is used in the production of yogurt and is believed to prolong human life by inhibiting the growth of proteolytic microbes in the intestinal tract; however, the culture will not survive in the digestive tract for prolonged periods of time. L. acidophilus and L. bifidus, on the other hand, are known to be able to retain their viability through the digestive tract, displacing proleolytic bacteria completely, thus affording a means of implantation in the lower intestinal tract. Both cultures have the faculties of maintaining a normal microbiological balance, particularly in the intestinal flora, suppressing many undesirable organisms while promoting a beneficial metabolism. L. acidophilus is completely non-pathogenic and offers an entirely safe, therapeutic regimen.
Until a few years ago, the beneficial effects resulting from the ingestion of L. acidophilus in cases of gastrointestinal disturbances were attributed to the simple outgrowth of the offending pathogen by the lactobacilli. Recently, a number of workers established that there is more to the reaction than just competition between strains. A by-product produced by L. acidophilus has been called variously antagonist (White and Hall, J. Dental Res. 48272, 1949); lactobacillin (Wheater et al., ATE Nature 168, 659, 1951); lactocidin (Vincent et al., J. Bact. 78, 479, 484, 1959); and antibiotic (Shahani et al., U.S. Pat. No. 3,689,640).
The form in which L. acidophilus has been usually employed to obtain its therapeutic effect has been as fermented milk. The number of viable organisms in acidophilus milk was usually in the order of 250 million per milliliter which produced a highly distasteful and for many a completely unpalatable product. In addition, the product had a relatively short useful life, usually limited to less than two weeks, which often created problems in distribution and handling. Moreover, the processing of such fermented milk as compared with ordinary milk was extremely expensive.
The beneficial effects of L. bifidus have also been recently reported (The Milk Industry, September, 1973). Here, it has been established that L. bifidus forms a substantial proportion of the intestinal flora of babies and performs an inhibiting effect on pathogenic bacteria and the growth of aerobic putrefactive microorganisms in the intestinal tract.
In efforts to improve the quality of my milk product, I have discovered that the milk initially secreted during the first few days after parturition, more commonly known as colostrum, can also be combined and made into a palatable milk product. Colostrum is known to contain high protein content which when added to milk provides a highly nutritional product without the need for any condensation. However, the possible benefits that could be gained from colostrum have been largely ignored because of its bitter taste.
Various processes that have been developed to prepare a multi-cultured milk product of this type have involved using yeast or alcohol which must necessarily interfere with the antibiotic effect of the bacteria since alcohol destroys bacteria. Various yogurt type products, as distinguished from ordinary dairy yogurt, have been produced by either a mixing together of separate fermented products such as in U.S. Pat. No. 1,899,817 (Matt) issuing on Feb. 28, 1933; high heat treatment as in U.S. Pat. No. 2,119,599 (Nordsiek) issuing on June 7, 1938; or alcoholic fermentation as in U.S. Pat. No. 2,824,804 (Mishima) issuing on Feb. 25, 1958. None of these processes, however, produce a palatable product and attempts to improve the flavor have not been satisfactory. The addition of flavors and sugar, particularly fresh fruits and berries, to the mixes undergoing the incubation stage has met with disflavor in that the incubation conditions have caused loss of flavor and color in the flavoring additives. Moreover, because the digestion of fruits and milk involve different enzymes and different digestive processes, such mixing may involve enzymatic and other conflicts ruining any such mixture as a health food. Milk should be consumed alone and not mixed with other foods. Other processing attempts have resulted in poorly controlled growth conditions which yield inferior quality taste, poor shelf life, as well as substantially altering the nutritional value of the milk product.
It is the purpose of this invention to provide a new nutritional and therapeutic milk product made by a multi-curdling process that will significantly reduce the unspent lactose after a buttermilk or sour cream type fermentation is completed or even yogurt fermentation and produce a product that is tasteful and can be digested by persons having an intolerance for lactose besides being more easily digested by anyone.
Another purpose of this invention is to improve upon the nutritional and therapeutic value of a milk product when transforming the lactose content by using various ingredients that individually are unpalatable but when combined in this invention produce an inexpensive tasteful milk product.
It is still another object of this invention to provide a food product with better flavor, consistency, and palatability than previously obtained when culturing a milk product with L. acidophilus or L. bifidus microorganisms.
In addition, the ingredients used in this invention not only produce a more desirable milk food product but provide for an inexpensive process that transforms the percentage of lactose into glucose and galactose by an amount heretofore thought impossible, thereby providing a food product that is more easily digestable by anyone and particularly by the multitude of people who cannot normally drink milk.
Other objects of the invention will be apparent from the following discussion and description of this invention.